xref: /openbmc/qemu/target/m68k/fpu_helper.c (revision dd873966) 
1 /*
2  *  m68k FPU helpers
3  *
4  *  Copyright (c) 2006-2007 CodeSourcery
5  *  Written by Paul Brook
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include "qemu/osdep.h"
22 #include "cpu.h"
23 #include "exec/helper-proto.h"
24 #include "exec/exec-all.h"
25 #include "exec/cpu_ldst.h"
26 
27 /* Undefined offsets may be different on various FPU.
28  * On 68040 they return 0.0 (floatx80_zero)
29  */
30 
31 static const floatx80 fpu_rom[128] = {
32     [0x00] = make_floatx80_init(0x4000, 0xc90fdaa22168c235ULL),  /* Pi       */
33     [0x0b] = make_floatx80_init(0x3ffd, 0x9a209a84fbcff798ULL),  /* Log10(2) */
34     [0x0c] = make_floatx80_init(0x4000, 0xadf85458a2bb4a9aULL),  /* e        */
35     [0x0d] = make_floatx80_init(0x3fff, 0xb8aa3b295c17f0bcULL),  /* Log2(e)  */
36     [0x0e] = make_floatx80_init(0x3ffd, 0xde5bd8a937287195ULL),  /* Log10(e) */
37     [0x0f] = make_floatx80_init(0x0000, 0x0000000000000000ULL),  /* Zero     */
38     [0x30] = make_floatx80_init(0x3ffe, 0xb17217f7d1cf79acULL),  /* ln(2)    */
39     [0x31] = make_floatx80_init(0x4000, 0x935d8dddaaa8ac17ULL),  /* ln(10)   */
40     [0x32] = make_floatx80_init(0x3fff, 0x8000000000000000ULL),  /* 10^0     */
41     [0x33] = make_floatx80_init(0x4002, 0xa000000000000000ULL),  /* 10^1     */
42     [0x34] = make_floatx80_init(0x4005, 0xc800000000000000ULL),  /* 10^2     */
43     [0x35] = make_floatx80_init(0x400c, 0x9c40000000000000ULL),  /* 10^4     */
44     [0x36] = make_floatx80_init(0x4019, 0xbebc200000000000ULL),  /* 10^8     */
45     [0x37] = make_floatx80_init(0x4034, 0x8e1bc9bf04000000ULL),  /* 10^16    */
46     [0x38] = make_floatx80_init(0x4069, 0x9dc5ada82b70b59eULL),  /* 10^32    */
47     [0x39] = make_floatx80_init(0x40d3, 0xc2781f49ffcfa6d5ULL),  /* 10^64    */
48     [0x3a] = make_floatx80_init(0x41a8, 0x93ba47c980e98ce0ULL),  /* 10^128   */
49     [0x3b] = make_floatx80_init(0x4351, 0xaa7eebfb9df9de8eULL),  /* 10^256   */
50     [0x3c] = make_floatx80_init(0x46a3, 0xe319a0aea60e91c7ULL),  /* 10^512   */
51     [0x3d] = make_floatx80_init(0x4d48, 0xc976758681750c17ULL),  /* 10^1024  */
52     [0x3e] = make_floatx80_init(0x5a92, 0x9e8b3b5dc53d5de5ULL),  /* 10^2048  */
53     [0x3f] = make_floatx80_init(0x7525, 0xc46052028a20979bULL),  /* 10^4096  */
54 };
55 
56 int32_t HELPER(reds32)(CPUM68KState *env, FPReg *val)
57 {
58     return floatx80_to_int32(val->d, &env->fp_status);
59 }
60 
61 float32 HELPER(redf32)(CPUM68KState *env, FPReg *val)
62 {
63     return floatx80_to_float32(val->d, &env->fp_status);
64 }
65 
66 void HELPER(exts32)(CPUM68KState *env, FPReg *res, int32_t val)
67 {
68     res->d = int32_to_floatx80(val, &env->fp_status);
69 }
70 
71 void HELPER(extf32)(CPUM68KState *env, FPReg *res, float32 val)
72 {
73     res->d = float32_to_floatx80(val, &env->fp_status);
74 }
75 
76 void HELPER(extf64)(CPUM68KState *env, FPReg *res, float64 val)
77 {
78     res->d = float64_to_floatx80(val, &env->fp_status);
79 }
80 
81 float64 HELPER(redf64)(CPUM68KState *env, FPReg *val)
82 {
83     return floatx80_to_float64(val->d, &env->fp_status);
84 }
85 
86 void HELPER(firound)(CPUM68KState *env, FPReg *res, FPReg *val)
87 {
88     res->d = floatx80_round_to_int(val->d, &env->fp_status);
89 }
90 
91 static void m68k_restore_precision_mode(CPUM68KState *env)
92 {
93     switch (env->fpcr & FPCR_PREC_MASK) {
94     case FPCR_PREC_X: /* extended */
95         set_floatx80_rounding_precision(80, &env->fp_status);
96         break;
97     case FPCR_PREC_S: /* single */
98         set_floatx80_rounding_precision(32, &env->fp_status);
99         break;
100     case FPCR_PREC_D: /* double */
101         set_floatx80_rounding_precision(64, &env->fp_status);
102         break;
103     case FPCR_PREC_U: /* undefined */
104     default:
105         break;
106     }
107 }
108 
109 static void cf_restore_precision_mode(CPUM68KState *env)
110 {
111     if (env->fpcr & FPCR_PREC_S) { /* single */
112         set_floatx80_rounding_precision(32, &env->fp_status);
113     } else { /* double */
114         set_floatx80_rounding_precision(64, &env->fp_status);
115     }
116 }
117 
118 static void restore_rounding_mode(CPUM68KState *env)
119 {
120     switch (env->fpcr & FPCR_RND_MASK) {
121     case FPCR_RND_N: /* round to nearest */
122         set_float_rounding_mode(float_round_nearest_even, &env->fp_status);
123         break;
124     case FPCR_RND_Z: /* round to zero */
125         set_float_rounding_mode(float_round_to_zero, &env->fp_status);
126         break;
127     case FPCR_RND_M: /* round toward minus infinity */
128         set_float_rounding_mode(float_round_down, &env->fp_status);
129         break;
130     case FPCR_RND_P: /* round toward positive infinity */
131         set_float_rounding_mode(float_round_up, &env->fp_status);
132         break;
133     }
134 }
135 
136 void cpu_m68k_set_fpcr(CPUM68KState *env, uint32_t val)
137 {
138     env->fpcr = val & 0xffff;
139 
140     if (m68k_feature(env, M68K_FEATURE_CF_FPU)) {
141         cf_restore_precision_mode(env);
142     } else {
143         m68k_restore_precision_mode(env);
144     }
145     restore_rounding_mode(env);
146 }
147 
148 void HELPER(fitrunc)(CPUM68KState *env, FPReg *res, FPReg *val)
149 {
150     int rounding_mode = get_float_rounding_mode(&env->fp_status);
151     set_float_rounding_mode(float_round_to_zero, &env->fp_status);
152     res->d = floatx80_round_to_int(val->d, &env->fp_status);
153     set_float_rounding_mode(rounding_mode, &env->fp_status);
154 }
155 
156 void HELPER(set_fpcr)(CPUM68KState *env, uint32_t val)
157 {
158     cpu_m68k_set_fpcr(env, val);
159 }
160 
161 #define PREC_BEGIN(prec)                                        \
162     do {                                                        \
163         int old;                                                \
164         old = get_floatx80_rounding_precision(&env->fp_status); \
165         set_floatx80_rounding_precision(prec, &env->fp_status)  \
166 
167 #define PREC_END()                                              \
168         set_floatx80_rounding_precision(old, &env->fp_status);  \
169     } while (0)
170 
171 void HELPER(fsround)(CPUM68KState *env, FPReg *res, FPReg *val)
172 {
173     PREC_BEGIN(32);
174     res->d = floatx80_round(val->d, &env->fp_status);
175     PREC_END();
176 }
177 
178 void HELPER(fdround)(CPUM68KState *env, FPReg *res, FPReg *val)
179 {
180     PREC_BEGIN(64);
181     res->d = floatx80_round(val->d, &env->fp_status);
182     PREC_END();
183 }
184 
185 void HELPER(fsqrt)(CPUM68KState *env, FPReg *res, FPReg *val)
186 {
187     res->d = floatx80_sqrt(val->d, &env->fp_status);
188 }
189 
190 void HELPER(fssqrt)(CPUM68KState *env, FPReg *res, FPReg *val)
191 {
192     PREC_BEGIN(32);
193     res->d = floatx80_sqrt(val->d, &env->fp_status);
194     PREC_END();
195 }
196 
197 void HELPER(fdsqrt)(CPUM68KState *env, FPReg *res, FPReg *val)
198 {
199     PREC_BEGIN(64);
200     res->d = floatx80_sqrt(val->d, &env->fp_status);
201     PREC_END();
202 }
203 
204 void HELPER(fabs)(CPUM68KState *env, FPReg *res, FPReg *val)
205 {
206     res->d = floatx80_round(floatx80_abs(val->d), &env->fp_status);
207 }
208 
209 void HELPER(fsabs)(CPUM68KState *env, FPReg *res, FPReg *val)
210 {
211     PREC_BEGIN(32);
212     res->d = floatx80_round(floatx80_abs(val->d), &env->fp_status);
213     PREC_END();
214 }
215 
216 void HELPER(fdabs)(CPUM68KState *env, FPReg *res, FPReg *val)
217 {
218     PREC_BEGIN(64);
219     res->d = floatx80_round(floatx80_abs(val->d), &env->fp_status);
220     PREC_END();
221 }
222 
223 void HELPER(fneg)(CPUM68KState *env, FPReg *res, FPReg *val)
224 {
225     res->d = floatx80_round(floatx80_chs(val->d), &env->fp_status);
226 }
227 
228 void HELPER(fsneg)(CPUM68KState *env, FPReg *res, FPReg *val)
229 {
230     PREC_BEGIN(32);
231     res->d = floatx80_round(floatx80_chs(val->d), &env->fp_status);
232     PREC_END();
233 }
234 
235 void HELPER(fdneg)(CPUM68KState *env, FPReg *res, FPReg *val)
236 {
237     PREC_BEGIN(64);
238     res->d = floatx80_round(floatx80_chs(val->d), &env->fp_status);
239     PREC_END();
240 }
241 
242 void HELPER(fadd)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
243 {
244     res->d = floatx80_add(val0->d, val1->d, &env->fp_status);
245 }
246 
247 void HELPER(fsadd)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
248 {
249     PREC_BEGIN(32);
250     res->d = floatx80_add(val0->d, val1->d, &env->fp_status);
251     PREC_END();
252 }
253 
254 void HELPER(fdadd)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
255 {
256     PREC_BEGIN(64);
257     res->d = floatx80_add(val0->d, val1->d, &env->fp_status);
258     PREC_END();
259 }
260 
261 void HELPER(fsub)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
262 {
263     res->d = floatx80_sub(val1->d, val0->d, &env->fp_status);
264 }
265 
266 void HELPER(fssub)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
267 {
268     PREC_BEGIN(32);
269     res->d = floatx80_sub(val1->d, val0->d, &env->fp_status);
270     PREC_END();
271 }
272 
273 void HELPER(fdsub)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
274 {
275     PREC_BEGIN(64);
276     res->d = floatx80_sub(val1->d, val0->d, &env->fp_status);
277     PREC_END();
278 }
279 
280 void HELPER(fmul)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
281 {
282     res->d = floatx80_mul(val0->d, val1->d, &env->fp_status);
283 }
284 
285 void HELPER(fsmul)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
286 {
287     PREC_BEGIN(32);
288     res->d = floatx80_mul(val0->d, val1->d, &env->fp_status);
289     PREC_END();
290 }
291 
292 void HELPER(fdmul)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
293 {
294     PREC_BEGIN(64);
295     res->d = floatx80_mul(val0->d, val1->d, &env->fp_status);
296     PREC_END();
297 }
298 
299 void HELPER(fsglmul)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
300 {
301     int rounding_mode = get_float_rounding_mode(&env->fp_status);
302     floatx80 a, b;
303 
304     PREC_BEGIN(32);
305     set_float_rounding_mode(float_round_to_zero, &env->fp_status);
306     a = floatx80_round(val0->d, &env->fp_status);
307     b = floatx80_round(val1->d, &env->fp_status);
308     set_float_rounding_mode(rounding_mode, &env->fp_status);
309     res->d = floatx80_mul(a, b, &env->fp_status);
310     PREC_END();
311 }
312 
313 void HELPER(fdiv)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
314 {
315     res->d = floatx80_div(val1->d, val0->d, &env->fp_status);
316 }
317 
318 void HELPER(fsdiv)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
319 {
320     PREC_BEGIN(32);
321     res->d = floatx80_div(val1->d, val0->d, &env->fp_status);
322     PREC_END();
323 }
324 
325 void HELPER(fddiv)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
326 {
327     PREC_BEGIN(64);
328     res->d = floatx80_div(val1->d, val0->d, &env->fp_status);
329     PREC_END();
330 }
331 
332 void HELPER(fsgldiv)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
333 {
334     int rounding_mode = get_float_rounding_mode(&env->fp_status);
335     floatx80 a, b;
336 
337     PREC_BEGIN(32);
338     set_float_rounding_mode(float_round_to_zero, &env->fp_status);
339     a = floatx80_round(val1->d, &env->fp_status);
340     b = floatx80_round(val0->d, &env->fp_status);
341     set_float_rounding_mode(rounding_mode, &env->fp_status);
342     res->d = floatx80_div(a, b, &env->fp_status);
343     PREC_END();
344 }
345 
346 static int float_comp_to_cc(int float_compare)
347 {
348     switch (float_compare) {
349     case float_relation_equal:
350         return FPSR_CC_Z;
351     case float_relation_less:
352         return FPSR_CC_N;
353     case float_relation_unordered:
354         return FPSR_CC_A;
355     case float_relation_greater:
356         return 0;
357     default:
358         g_assert_not_reached();
359     }
360 }
361 
362 void HELPER(fcmp)(CPUM68KState *env, FPReg *val0, FPReg *val1)
363 {
364     int float_compare;
365 
366     float_compare = floatx80_compare(val1->d, val0->d, &env->fp_status);
367     env->fpsr = (env->fpsr & ~FPSR_CC_MASK) | float_comp_to_cc(float_compare);
368 }
369 
370 void HELPER(ftst)(CPUM68KState *env, FPReg *val)
371 {
372     uint32_t cc = 0;
373 
374     if (floatx80_is_neg(val->d)) {
375         cc |= FPSR_CC_N;
376     }
377 
378     if (floatx80_is_any_nan(val->d)) {
379         cc |= FPSR_CC_A;
380     } else if (floatx80_is_infinity(val->d)) {
381         cc |= FPSR_CC_I;
382     } else if (floatx80_is_zero(val->d)) {
383         cc |= FPSR_CC_Z;
384     }
385     env->fpsr = (env->fpsr & ~FPSR_CC_MASK) | cc;
386 }
387 
388 void HELPER(fconst)(CPUM68KState *env, FPReg *val, uint32_t offset)
389 {
390     val->d = fpu_rom[offset];
391 }
392 
393 typedef int (*float_access)(CPUM68KState *env, uint32_t addr, FPReg *fp,
394                             uintptr_t ra);
395 
396 static uint32_t fmovem_predec(CPUM68KState *env, uint32_t addr, uint32_t mask,
397                                float_access access)
398 {
399     uintptr_t ra = GETPC();
400     int i, size;
401 
402     for (i = 7; i >= 0; i--, mask <<= 1) {
403         if (mask & 0x80) {
404             size = access(env, addr, &env->fregs[i], ra);
405             if ((mask & 0xff) != 0x80) {
406                 addr -= size;
407             }
408         }
409     }
410 
411     return addr;
412 }
413 
414 static uint32_t fmovem_postinc(CPUM68KState *env, uint32_t addr, uint32_t mask,
415                                float_access access)
416 {
417     uintptr_t ra = GETPC();
418     int i, size;
419 
420     for (i = 0; i < 8; i++, mask <<= 1) {
421         if (mask & 0x80) {
422             size = access(env, addr, &env->fregs[i], ra);
423             addr += size;
424         }
425     }
426 
427     return addr;
428 }
429 
430 static int cpu_ld_floatx80_ra(CPUM68KState *env, uint32_t addr, FPReg *fp,
431                               uintptr_t ra)
432 {
433     uint32_t high;
434     uint64_t low;
435 
436     high = cpu_ldl_data_ra(env, addr, ra);
437     low = cpu_ldq_data_ra(env, addr + 4, ra);
438 
439     fp->l.upper = high >> 16;
440     fp->l.lower = low;
441 
442     return 12;
443 }
444 
445 static int cpu_st_floatx80_ra(CPUM68KState *env, uint32_t addr, FPReg *fp,
446                                uintptr_t ra)
447 {
448     cpu_stl_data_ra(env, addr, fp->l.upper << 16, ra);
449     cpu_stq_data_ra(env, addr + 4, fp->l.lower, ra);
450 
451     return 12;
452 }
453 
454 static int cpu_ld_float64_ra(CPUM68KState *env, uint32_t addr, FPReg *fp,
455                              uintptr_t ra)
456 {
457     uint64_t val;
458 
459     val = cpu_ldq_data_ra(env, addr, ra);
460     fp->d = float64_to_floatx80(*(float64 *)&val, &env->fp_status);
461 
462     return 8;
463 }
464 
465 static int cpu_st_float64_ra(CPUM68KState *env, uint32_t addr, FPReg *fp,
466                              uintptr_t ra)
467 {
468     float64 val;
469 
470     val = floatx80_to_float64(fp->d, &env->fp_status);
471     cpu_stq_data_ra(env, addr, *(uint64_t *)&val, ra);
472 
473     return 8;
474 }
475 
476 uint32_t HELPER(fmovemx_st_predec)(CPUM68KState *env, uint32_t addr,
477                                    uint32_t mask)
478 {
479     return fmovem_predec(env, addr, mask, cpu_st_floatx80_ra);
480 }
481 
482 uint32_t HELPER(fmovemx_st_postinc)(CPUM68KState *env, uint32_t addr,
483                                     uint32_t mask)
484 {
485     return fmovem_postinc(env, addr, mask, cpu_st_floatx80_ra);
486 }
487 
488 uint32_t HELPER(fmovemx_ld_postinc)(CPUM68KState *env, uint32_t addr,
489                                     uint32_t mask)
490 {
491     return fmovem_postinc(env, addr, mask, cpu_ld_floatx80_ra);
492 }
493 
494 uint32_t HELPER(fmovemd_st_predec)(CPUM68KState *env, uint32_t addr,
495                                    uint32_t mask)
496 {
497     return fmovem_predec(env, addr, mask, cpu_st_float64_ra);
498 }
499 
500 uint32_t HELPER(fmovemd_st_postinc)(CPUM68KState *env, uint32_t addr,
501                                     uint32_t mask)
502 {
503     return fmovem_postinc(env, addr, mask, cpu_st_float64_ra);
504 }
505 
506 uint32_t HELPER(fmovemd_ld_postinc)(CPUM68KState *env, uint32_t addr,
507                                     uint32_t mask)
508 {
509     return fmovem_postinc(env, addr, mask, cpu_ld_float64_ra);
510 }
511